Lint JavaScript/TypeScript files via the official ESLint MCP server

{
  "server": "@eslint/mcp",
  "version": "0.3.6",
  "sdk": "@modelcontextprotocol/[email protected]",
  "transport": "stdio",
  "framing": "ndjson",
  "launch": "npx @eslint/mcp",
  "handshake": [
    {
      "direction": "client→server",
      "message": {
        "jsonrpc": "2.0",
        "id": 1,
        "method": "initialize",
        "params": {
          "protocolVersion": "2024-11-05",
          "capabilities": {},
          "clientInfo": {
            "name": "pathfinder-probe",
            "version": "1.0.0"
          }
        }
      }
    },
    {
      "direction": "server→client",
      "elapsed_ms": 236,
      "message": {
        "result": {
          "protocolVersion": "2024-11-05",
          "capabilities": {
            "tools": {
              "listChanged": true
            }
          },
          "serverInfo": {
            "name": "ESLint",
            "version": "0.3.6"
          }
        },
        "jsonrpc": "2.0",
        "id": 1
      }
    },
    {
      "direction": "client→server",
      "message": {
        "jsonrpc": "2.0",
        "method": "notifications/initialized"
      }
    },
    {
      "direction": "client→server",
      "message": {
        "jsonrpc": "2.0",
        "id": 2,
        "method": "tools/list",
        "params": {}
      }
    },
    {
      "direction": "server→client",
      "elapsed_ms": 238,
      "message": {
        "result": {
          "tools": [
            {
              "name": "lint-files",
              "description": "Lint files using ESLint. You must provide a list of absolute file paths to the files you want to lint.",
              "inputSchema": {
                "type": "object",
                "properties": {
                  "filePaths": {
                    "type": "array",
                    "items": {
                      "type": "string",
                      "minLength": 1
                    },
                    "minItems": 1
                  }
                },
                "required": ["filePaths"],
                "additionalProperties": false
              }
            }
          ]
        },
        "jsonrpc": "2.0",
        "id": 2
      }
    }
  ],
  "tool_call": {
    "direction": "client→server",
    "message": {
      "jsonrpc": "2.0",
      "id": 3,
      "method": "tools/call",
      "params": {
        "name": "lint-files",
        "arguments": {
          "filePaths": ["/tmp/eslint-mcp-test/test.js"]
        }
      }
    }
  },
  "tool_result": {
    "direction": "server→client",
    "elapsed_ms": 287,
    "message": {
      "result": {
        "content": [
          {
            "type": "text",
            "text": "Here are the results of running ESLint on the provided files. Before doing anything else, you must display the full list to the user:"
          },
          {
            "type": "text",
            "text": "{"filePath":"/tmp/eslint-mcp-test/test.js","messages":[{"ruleId":"no-unused-vars","severity":2,"message":"'y' is assigned a value but never used.","line":2,"column":5},{"ruleId":"no-undef","severity":2,"message":"'console' is not defined.","line":3,"column":1},{"ruleId":"no-unused-vars","severity":2,"message":"'unused' is defined but never used.","line":5,"column":10},{"ruleId":"no-constant-condition","severity":2,"message":"Unexpected constant condition.","line":9,"column":5},{"ruleId":"no-unused-vars","severity":2,"message":"'z' is assigned a value but never used.","line":10,"column":7}],"errorCount":5,"fatalErrorCount":0,"warningCount":0}"
          },
          {
            "type": "text",
            "text": "If the user asked to fix any issues found, proceed in fixing them."
          }
        ]
      },
      "jsonrpc": "2.0",
      "id": 3
    }
  },
  "test_file_content": "var x = 1;
var y = 2;
console.log(x)

function unused() {
  return 42;
}

if (true) {
  var z = "hello"
}
",
  "eslint_config": "import js from '@eslint/js';
export default [js.configs.recommended];",
  "total_latency_ms": 287,
  "errors_found": 5,
  "rules_triggered": ["no-unused-vars", "no-undef", "no-constant-condition"]
}